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Everything at the scene was collected by police, including a plastic bag found near the body.

The woman, believed to be in her mid-40s, tentatively has been identified, but her name was not released because family had not been notified, said John Hansons, deputy coroner for Benton County.

She is believed to be a Tri-City resident, but it's unknown which city she lived in, Hansons added.

Hansons is acting deputy coroner until he officially takes over as Benton County coroner on Jan. 1.

"An autopsy is scheduled for Wednesday," he said.

Columbia Basin Dive Rescue officials were called to recover the body, which was face-down in about a foot of water and five inches of mud, said Scott Ruppelius, operations director with the dive and rescue unit.